Fuse



Oct. 4, 1932.

J. R; FOGAL FUSE Filed March 4, 1931 Patented Oct. 4, 1932 PATENT OFFICE JAY R. FOG-AL, OF SAN FRANCISCO, CALIFORNIA FUSE Application filed March 4,

This invention relates to fuses and has particular reference to electrical fuses that are vented to permit the gases to escape which are generated when the fuse link is melted.

The primary object of the present invention is to provide a fuse which shall consist of few parts that are simple in construction and inexpensive to manufacture and which, when assembled, shall provide a fuse that is light in weight.

Another object is to provide a fuse of this character which shall include a tortuous ventilating passage which extends from the interior of the fuse to the atmosphere, thereby providing a vent for the gases generated when the fuse link melts, which passage shall effectively cool the gases and reduce the fire hazard to a minimum.

A further object is to provide a. fuse structure which shall be equally adaptable to large and small size fuses.

With the foregoing and other objects in view, the invention may be stated to consist in the various novel features of construction and arrangement or combination, all of which will be fully described hereinafter and pointed out in the appended claims.

7 In the drawing accompanying and forming part of this application,

Fig. 1 is a view partly in elevation and partly in section of a fuse constructed in accordance with my invention;

Fig. 2 is a similar view of a modified form of fuse;

Fig. 3 is a perspective view of one of the cup-shaped members used in the construction shown in Fig. 2;

Fig. 4: is a perspective view of the lock washer used in the construction shown in Fig. 2, and

Figs. .5 and 6 are top plan views of the lock washer and sleeve.

Describing the various parts by reference characters and referring particularly to Fig. 1, 1 denotes the body portion of the fuse which in the present instance is made of insulating material and is in the form of a cylinder having internal threads at each end. All internally and externally threaded sleeve 1931. Serial No. 520,131.

2 is engaged with each threaded end of the body portion and these sleeves are fastened in position by a rivet 3 or other suitable fastening means. The sleeve 2 is shown in the present instance as being formed from sheet metal and the threads thereon are rolled for economy in manufacture.

Positioned within each sleeve is a cupshaped member 4 which contacts with the internal thread of the sleeve and defines a tortuous passage 5. The member 4 may be secured to the sleeve 2 in any suitable manner, as by a snug frictional contact, or by brazing or in any other suitable manner. The inner end of the cup-shaped member is preferably rounded as indicated at 6 to provide a wide entrance for the gases to the tortuous passage 5. A sheet metal cap 7 is threaded on the outer end of the sleeve 2 and is provided with a plurality of vent ports 8 which establish communication between the atmosphere and the passage 5. A fuse link 9 extends longitudinally through the fuse body and each end thereof is clamped between the cap 7 and the end wall of cupshaped member 4.

When the fuse link blows or melts, the gases generated find their way to the atmosphere through the spiral passages 5 and vent ports 8 and are thus cooled by contact with the thin sheet metal members 4 and 5. Due to the relatively few parts composing this fuse and their simplicity, it will be obvious that the fuse can be manufactured very cheaply and the resultant fuse will be extremely light in weight and a large saving in transportation charges will be efi'ected when shipments are made.

In Fig. 2 I have shown amodified construction adapted for larger size fuses such as employ knife blade contacts. an insulating body 10 is used which is internally and externally threaded at each end. A cup-shaped member 11 is positioned in each end of the body portion in contact with the internal threads to define a spiral vent passage 12. The cup shaped member may be secured to the body portion 10 by snug frictional contact, or by rivets 11 or in any other suitable or approved manner. The end wall In this form,

of this member is formed with an embossed 'eccentrically disposed portion 13, and a diametrically extending slot 14 through which the knife blade contact 17 is adapted to project. As shown in Fig. 3, the slot 14: extends entirely across the boss 13 and to points adjacent the marginal edges of the cup-shaped member. A look ring 15 is rotatably mount edon the end of the member 11 and is formed with an eccentric opening that is adapted to receive the embossed portion 13. This lock ring is'also provided with a slot 16 which will align with slot 14 when the ring is rotated to the position shown in Fig. 6. Normally when ring 15 is positioned withits outer edge concentric with the edge of the cup-shaped member as shown in Fig. 5, the edges of slot 1 1 will be overlapped by the lock ring. The knife blade contacts 17 are notched as indicated at 17 and these notches are adapted to be engaged by the lock ring when in the position shown in Fig. 5 to retain the knife blade contacts in position and relieve the fuse link 18 interconnecting said blades from strain.

A metal cap 19 having an inwardly directed portion 20 is threaded on each end of the fuse body and engages the lock washer to hold the same in position. These caps are formed with a plurality of vent ports 21 which establish communication between the spiral passage 12 and the atmosphere.

This type of fuse is renewable by removing the end caps 19 and locking ring 15, whereupon the knife blades and fuse link may be withdrawn from the fuse body and a new link substituted therefor and the parts reassembled.

l/Vhat I claim is:

1. A fuse of the character set forth comprising a body portion having internally and externally threaded end portions, a member positioned in each end in engagement with the internal threads to define a spiral passage, a cap engaging the external thread at each end of said body portion and having a plurality of vent ports establishing communication between said passage and the atmosphere, and a fuse link positioned within said body portion.

2. A fuse of the character set forth comprising a body portion having internally and externally threaded end portions, a cupshaped member positioned in each end of said body portion in engagement with said internal threads to define a spiral passage, a cap fitted to each end of said body portion and engaging said external threads, said caps having vent ports communicating with said 7 spiral passages, and a fuse link positioned within said body portion.

3. A fuse of the character set forth comprising a body portion of insulating material, internally and externally threaded sleeves projecting from said body portion and forming a continuation thereof, a cupshaped member engaging said internal threads in each sleeve, and defining a spiral passage, a cap engaging the external threads on each sleeve and normally closing said body portion, said caps having vent ports communicating with said spiral passages, and a fuse link interconnecting said caps.

1. A fuse of the character set forth comprising a body portion of insulating material, a sheet metal sleevehaving a rolled internal and external thread projecting from each end of said body portion and forming a continuation thereof, a sheet metal cup shaped member positioned within each sleeve and engaging the internal threads thereof to define a spiral passage, and a sheet metal cap engaging the external thread on each sleeve and normally closing said body portion, said caps having a plurality of vent ports communicating with said spiral passages, and a fuse link interconnecting said caps.

5. A fuse of the character set forth comprising a body portion of insulating material, said body portion having internal and external threaded end portions, a cupshaped member positioned within each end of said body portion in engagement with said internal thread to define a spiral passage, said cup shaped members each having an embossed portion and a slot in the end wall thereof, knife blade contacts projecting through said slots, a lock ring embracing each of said embossed portions and engaging shoulders on said knife blades, caps threaded on said external threads and engaging said lock washers, said caps each having a plurality of vent ports communicating with said spiral passages, and a fuse link interconnecting said knife blade contacts.

In testimony whereof I affix my signature.

JAY R. FOGAL; 

